1. Field of the Invention
This invention relates generally to a vehicle jack and, in particular, to a jack for lifting a motorcycle.
2. Description of the Prior Art
It is often necessary, while repairing or servicing a motorcycle, to lift the motorcycle to a position in which both wheels are suspended. The jack devices which are known in the art are positioned underneath the central portion of the motorcycle and lift the motorcycle by the frame so that both wheels are suspended to perform the servicing operation.
One of such known jack devices consists of a plurality of horizontal members which are positioned orthogonally to the orientation of the motorcycle. These horizontal members are interconnected by pivotal support members such that when erect, the jack takes the form of a rectangular frame. One of the supporting members has a lever attached to it. This lever is positioned so that when the jack is in the erect position, the lever is substantially parallel to the motorcycle orientation. In order to operate this device, one must slide the collapsed jack underneath the motorcycle so that the horizontal members are positioned underneath the central portion of the motorcycle, and with the lever positioned substantially vertical. The operator must then steady the device with his foot and rotate the lever into a position which is substantially parallel to the motorcycle orientation. Rotating the lever causes the support members to pivot to raise the horizontal members thereby moving the jack to its erect position to lift the motorcycle so that both wheels are suspended. Such a device is available from Easyrider of Agoura Hills, Calif. under the names EZ-Lift and Duo-Lift.
This device has limited application because it only provides a single motorcycle lift height which is determined by the jack when in its erect position. In addition, this device does not provide sufficient safety measures to lock the jack in its erect position. Furthermore, lifting the motorcycle with this device requires substantial exertion on the part of the operator.
A second jack device known in the art consists of a base and a platform structure attached to the base by four pivotally connecting legs. A pneumatic cylinder is attached to the base. The pneumatic cylinder piston operates on at least one of the legs. In the collapsed position, the device is placed underneath the central portion of the motorcycle. The pneumatic cylinder is activated which pulls the legs to pivot them thereby lifting the platform structure into an upright position. Accordingly, lifting of the motorcycle is effected. A device of this kind is available from Camton Mechanical of Columbus, Ohio under the name Quicklift.
This device requires the application of a substantial amount of force to be applied in order to effect the pulling of the legs to effect the lifting.
The present invention minimizes the problems discussed with respect to the prior art and provides a vehicle jack which operates through a range of positions providing a stabilized jack which requires a relatively small amount of force to effect the lifting of the motorcycle.